Varying Degrees of Being Another
Once again, let’s leave the science-fiction scenarios behind and just think about everyday events. I sit in a plane coming in for a landing and overhear random snippets of conversations around me — remarks about how great the Indianapolis Zoo is, how there’s a new delicatessen at Broad Ripple, and so forth. Each snippet carries me a smidgen into someone else’s world, gives me the tiniest taste of someone else’s viewpoint. I may resonate very little with that viewpoint, but even so, I am entering ever so slightly into that person’s “private” universe, and this incursion, though absolutely trivial for a human being, is far deeper than any canine’s incursion into another canine’s universe ever was.
And if I have untold thousands of hours of conversation with another human being on topics of every imaginable sort, including the most private feelings and the most confidential confessions, then the interpenetration of our worlds becomes so great that our worldviews start to fuse. Just as I could jump to California when talking on the telephone with Scott Kim in the Imlac room, so I can jump inside the other person’s head whenever, through words and tones of voice, they call forth their most fervent hopes or their most agonizing fears.
To varying degrees, we human beings live inside other human beings already, even in a totally nontechnological world. The interpenetration of souls is an inevitable consequence of the power of the representationally universal machines that our brains are. That is the true meaning of the word “empathy”.
I am capable of being other people, even if it is merely an “economy class” version of the act of being, even if it falls quite a bit short of being those people with the full power and depth with which they are themselves. I have the good fortune — at least I usually consider it fortunate, though at times I wonder — of always having the option of falling back and returning to being “just me”, because there is only one primary self housed in my brain. If, however, there were a few high-powered selves in my brain, all competing with each other for primacy, then the meaning of the word “I” would truly be up for grabs.
The Naive Viewpoint is Usually Good Enough
The image I just conjured up of several selves competing for primacy inside one brain may have struck you as extremely weird, but in fact the experience of internal conflict between several “rival selves” is one that we all know intimately. We know what it is to feel split between wanting to buy that candy bar and wanting to refrain. We know what it is to feel split between driving “just another twenty miles” and pulling off at the next rest stop for a desperately needed nap. We know what it is like to think, “I’ll just read one more paragraph and then go fix dinner” and also to think, “I’ll just finish this chapter first.” Which one of these opposing inner voices is really
If you simultaneously dip your left hand into a basin of hot water and your right hand into a basin of ice water, leave them both there for a minute, and then plunge them into a lukewarm sink, you will find that your two hands — usually your most reliable scouts and witnesses of the outer world — are now telling you wildly opposite things about the very same sinkful of water. In reaction to this paradox, you will most likely just shrug and smile, thinking to yourself, “What a strong tactile illusion!” You aren’t likely to think to yourself, “This cognitive split inside my brain is the thin edge of the wedge, revealing the illusoriness of the everyday conviction that there is just a single self inside my head.” And the reason nearly everyone would put up great resistance to such a conclusion is that for nearly all purposes, the simple story we tell ourselves is good enough.
This situation is a bit reminiscent of Newtonian physics, whose laws are extraordinarily reliable unless there are objects moving near each other with a relative velocity approaching the velocity of light, and in such cases Newtonian physics goes awry and gives very wrong answers. There is no reason at all, however, to abandon Newtonian physics in most familiar situations, even including the calculations of the orbits of spacecraft traveling to the moon or other planets. The velocities of such spacecraft, although huge compared with those of jet airplanes, are still minuscule fractions of the speed of light, and abandonment of Newton is not in the least called for.
Likewise, why should we abandon our commonsense attitudes about how many souls inhabit our brains when we know very well that the answer is just
Where Does a Hammerhead Shark Think it is?
Perhaps the most forceful-seeming challenge to the thesis that a single soul — your own, say — is parceled out among a number of distinct brains is simply the question, “Okay, let’s suppose that I’m somehow distributed over many brains. Then which one do
If these examples are too far-fetched or too technological for your taste, then just think of the lowly hammerhead shark. The poor thing has eyes on opposite sides of its head, which look out, quite often, on two completely unrelated scenes. So which scene is the shark
To put things in somewhat sharper focus, let’s invent a variation on the hammerhead shark. We’ll posit a creature whose eyes are taking in one situation (say in Bloomington) and whose ears are taking in another, unrelated situation (say in Stanford). The same brain is going to process these inputs at the same time. I hope you won’t claim that this is an impossible feat! If that’s your inclination, please first recall that you drive your car while reacting to other cars, scenery, billboards, and roadsigns, and also while talking with a far-off friend on your cell phone (and the topics covered in the conversation may vividly transport you to yet other places), and all during that very same period a recently-heard tune is running through your head, your strained back is bugging you, you smell cow manure wafting through the air, and your stomach is shouting to you, “I am hungry!” You manage to process all those different simultaneous worlds perfectly well — and in that same spirit, nothing is going to prevent a human brain from dealing simultaneously with the two unrelated worlds of Stanford sounds and Bloomington sights, no more than the hammerhead shark’s brain protests, “Does not compute!” So the idea “I cannot be simultaneously here and there” goes down in flames. We
Sympathetic Vibrations
But perhaps you feel that what I’ve just described doesn’t address the question originally posed about which of many brains
If I claim that I am partially in my sister Laura and she is partly in me, it seems nonetheless obvious that if